Roll roofing fastener



Dec.'6, 1938. H. M. MAzE ROLL RooFING FASTENER Fil'ed Feb. '15, 1937Patented 6, 1938 ROIL BOOFING FA'STENER Hamilton M. Maze, Peru, lll.,aslignortow. HL l Maze Company, Pern, Ill., a corporation of IllinoisApplication February 13, 1937, Serial No. 125,524

, n 6A This invention relates to roll roofing, and more .particularly toa fastener of the nail type which will securely hold so-called rollroofing on a roof for an extended period of time and fully meet all ofthe desirable requirements of the roofing manufacturers, dealers andusers. Recent years have seen a general advance and improvement in thequality of all types of roofing, and it is well recognized, for example,that asphalt 1o roll roolngs are at a high state of perfection. By meansof accelerated atmospheric conditions, in which air, water, heat, cold,and even intense artificial sunlight are all faithfully reproduced, rollroofing can now, for the purpose of testing, be artificially weatheredin a few days time. These few days are equivalent to years of normalout-of-door conditions. As a result, asphalt rooflngs, in theirrespective grades, have passed and are passing through tests andchecking methods so rigorous that the factors making for their long lifeare well known and the finished productis high in quality, long life anduniformity.

l However, the best roll roofing must still be de- 26 pendent on itsfastening, and while the roll roofing itself is very satisfactory forthe purpose and may.. be secured in place by means of ordinary roofingnails, the finished roof may be unsatisfactory after a comparativelyshort period. of time 30 on account of the limited holding power of thefasteners, and the ineiilciency of the sealing means. t

The completed roof secured in the ordinary manner, is apparently verysatisfactory for a short time. However, the nails or other fastenerssoon become loose or even entirely remoyed, a condition known to thetrade as drawing, easing ou or popping. `This causes` a great deal ofdissatisfaction with this type of roof; and it is necessary for roofmanufacturers,. dealers and contractors to make many costly adjustmentson roofs of this type. 'Ihe fastenersfordinarily used are unsatisfactoryfor several reasons. For-4nstance, the shank does not .have sufllcientholding power. Also the opening formed bythe shank l when driven.through the roofing cannot be properly sealed by the ordinary nailhead.` Therefore, moisture may enter under the head and around theshank, ultimately'destroying the 60 setting -and also causing the nailsto rust, and

the roof will no longer be held securely in place.

To provide a satisfactory and permanent roof under all: normalconditionsl has' been a very serious problemand it is essentialy thatthe fas- 56 tenets` or nails shlouldrnot become even slightly (Cl.10B-33) loosened as this causes the roof `to leak around the shank ofthel fastener, and even when a leak is not immediately apparent anyaccess of moisture under the head of the nail or to the fibres ofA thewood surrounding the nail shank will cause .5 the nail to be forcedoutwardly. I

It is desirable that the holding power of the shank should be greatlyincreased over that of fasteners in common use at the present time, andthat the shank should be of such size, structure 10 and length that thesheathing will not be split and large slivers will not be knocked outfrom the under side thereby reducing the holding power by a largepercentage. Also the nail head must be such as tol snugly fit theinequalities of the roof 15 and prevent access of moisture thereunder.

It is therefore an object of the present invention to provide a fastenerof the nail type in which the holding power is greatly increased andwill be effective to retain the roofing material snugly in 20 place overa period of time considerably longer than has'heretofore been possible,and in which the vhead of the fastener is of such a type that it willprevent moisture from entering thereunder and will effectively seal theopening made by thef 2tv In lthe application of roll roofing," fastenershaving rigid heads integral with the shank have not been satisfactorybecause roofing nails are often driven at an angle, and also have atendency to 30 -tilt under the hammer thus causing an uneven clampingaction of the rigid head against the roofing thereby allowing .moistureto enter under the head. Also this tilting, or even irregularities itthe thickness of therroll roofing or in the surface 35 o the sheathing,may cause the rigid'head to clamp unevenly and -angular1y, often cuttingor otherwise'injuring the roll roofing. It is therefore an object toprovide afastener in which the holding power and sealing characteristicsare un- 40 usually efi'ctive even when lthe .nail is driven at an angle.In order to secure the maximum holding power in a roofing nail of this"type the shank of the Y nail must be of such size and constructionthatit 45 will not unduly injure or displacethe fibres of thesheathingto which it is applied. .Alsoit must be easily driven with a hammerinthe ordinary manner without splitting the wood even for a shortdistance, as any splitting of the wood or crushing of fibres reduces theholdingefficiency thereof. It is also desirable that the nail should nottilt veasily under the hammer. l

The present invention overcomes all of the above noted objections toprior devices and it is 56.

therefore an object to provide a nail for fastening fabric base rollroofing to roof sheathing, in which all of the component parts are socorrelated and coordinated with special reference to form. and dimensionthat when applied in the normal manner unusual holding power and sealingqualities are obtained.

It is a further object to provide a fastener of the character describedhaving the above noted desirable characteristics in whichthe holethrough the roll roofing made by the shank of the fastener will not bedistorted and will conform snugly to the cross-sectional contour of thefastener and particularly that part of the fastener adjacent the head,and the head will conform to the sur-- face of the roll roofing andclamp snugly over its entire lower surface.

It is also an object to provide a fastener of the character described inwhich the shank is small relative to the diameter of the head and whichwill not rotate while being driven in the sheathing under a normal blowof the hammer, and will not materially tear or distort the fibres of thewood to thereby reduce their holding engagement with th-e shank overlong periods of time.

As previously pointed out, the permanence of the roof depends uponeiiicient sealing combinedk with great holding power. The presentinvention provides such a combination of desirable characteristics andthe holding power of fasteners made in accordance with this inventionhas been found by actual tests to be many times greater than that of anyother fasteners in common use.

Many expedients have been resorted to in attempting to provide the shankwith more holding power. High pitched threads which cause the nail toturn as it is being driven in have been used. It has been commonpractice to merely form barbs on the shanks to provide projections or aroughened surface-which it was thought tended to increase the holdingpower. However, the increased holding power has been very slight and thebarbs make an irregular hole through the roofing material.

It is therefore an object of the present invention to provide a fastenerin which the shank is provided with means for greatly increasing theholding power of the nail without causing rotation of the nail when itis being driven in place and without material destruction of the woodflbers, whereby the nails may be used to secure roll roofing to verythin sheathing of various types, with sufficient holding power to retainthe covering snugly in place and prevent leakage under extreme weatherconditions and over long periods of time.

In order to meet the requirements of established standards in the trade,it is desirable to provide nails in which each standard gauge andcorresponding length will meet standard tests as to cross sectionalstrength and which will provide a predetermined count per pound. If thematerial of the shank is cut away or it is reduced in cross section atcertain points, to increase holding power, then the size `or gauge oftheshank must be increased to provide standard'cross sectional strength.If this is done the count per pound is reduced and the stock or totalamount of material used for a predetermined count is increased, whichadds materially to the manufacturing and transportation costs.

It is therefore a. very important object of the present invention toprovide a nail of the character described having materially-increasedholding power and which will satisfactorily meet standard requirementswith respect to gauge of stock, cross sectional strength, and count perpound.

As previously stated, nails with high pitch threads tend to ease out.That is, the strains caused by expansion of the roofing and otherconditions cause the nails to rotate backward slightly and theygradually work out sufficiently to loosen the roof covering and also topermit moisture to enter through the opening around the nail shank. Itis therefore an object of this invention to provide a nail which willnot ease out but which will remain fixed in holding position until apull equivalent to its maximum holding power is applied.

In order to prevent rust, it is desirable to galvanize nails of thistype. However, it has been found thatif ordinary annular grooves areprovided in the shank to increase holding power, the nails may not beproperly galvanized for the reason that the galvanizing material doesnot flow evenly over the surface, nor does the surplus metal drainfreely, but instead accumulates in these annular grooves, and thereforethe coating is very rough and uneven and tends to destroy the woodfibers and prevent their engaging in the grooves. The galvanizingmaterial tends to more or less completely ll such grooves and forms arough and uneven surface over the shank of the nail.

sheathing has been materially reduced in thickness as compared to oldstandards, and a new type of sheathing comprising laminated wood haslately been introduced in an effort to reduce the thickness to a minimumconsistent with strength. The laminated sheathing is made of a pluralityof thin sheets of wood which may be veneer and which are glued togetherwith the grain of adjacent sheets in cross wise relation. sheathing ofthis typeis sometimes as thin as five-sixteenths of an inch and it isessential that the nails used should have maximum holding power, as onlya small area of the nail is engaged by the wood flbers. The presentinvention contemplates anail particularly adapted for use with such thinsheathing and having materially increased holding power.' in proportionto the area engaged by the wood bers. t

The present invention, therefore, provides a highly eflicient means forincreasing the holding power of the shank in combination with a flexibleor resilient sealing means whereby a snug weatherproof engagement ismaintained for a very ylong period of time regardless of expansion andcontraction of the roofing material by extreme weather conditions, also,a construction is provided which may `easily be galvanized or otherwisecoated.

Further objects will be apparent from the specification and the appendedclaims.

In the drawing:

Fig. 1 is an enlarged side elevation of one of the nails as applied to aroof, the roll roofing and sheathing being shown in section.

Fig. 2 is a side elevation similar to Fig. 1, but illustrates theadaptability of the head when the fastener is driven in a tilted orangular position.

Fig. 3 is a fragmentary view of the nail as used inconnection withcomparatively thin laminated sheathing.

Fig. 4 is a view similar to Fig. 3, but illustrates the nail as usedwith very thin laminated sheathmg.

Fig. 5 is an enlarged fragmentary detail of the shank, partly in sectionbetter to illustrate the galvanized coating.

fil

Fig. 6 is a full size elevation of the fastener.

Referring to the drawing in detail, the embodiment illustrated comprisesrelatively small, short, threaded shank l having a comparatively largeand very thin head 2 thereon. The entire nail is preferably of malleablematerial, whereby the thin head maybe more or less flexible to conformto uneven surfaces, and sumciently resilient to retain a sealingrelationship under extreme weather conditions.

The shank may be sharply pointed at t and is provided with a low pitchhelical groove t preferably formed by rolling the shank so that nomaterial is 'out away and the original cross section of the shank isretained. The groove preferably forms a buttress type helical shoulder 5so that when the nail is driven in place the wood bers engage over theshoulder as shown in Fig. 5 and the holding power of the nail is therebygreatly increased.

'I he lower surface of the groove forming the shoulder is substantiallyperpendicular tothe axis of the nail and the remaining surface forms acomparatively small angle with the axis of the nail. This provides along substantially flat helical shoulder which may extend completelyover that portion of the shank which is driven vinto the supprt. It hasbeen found preferable, however, to terminate the shoulder a shortdistance from the point of the nail to provide a pilot portion l asshown. @This is somewhat more elfective in'driving the nails and alsoprevents excessive rupture of the wood bers. A

The smooth surfaces' of the angular sides 'l of the groove force theends of the fibers outward While the nail is being driven withoutmaterially breaking or crushing them and enables their down-turned endsto spring inwardly over the shoulder as shown in Fig. 5, therebyprovidingl very great holding powr with no tendency for the nail torotate whil being driven.

During the nal seating of the nail, the flexible head makes possible itsadjustment to the surface of the roong in such a way as to compress theroofing material snugly around the shank and between the head and thesheathing, thereby making a snug weatherproof engagement, which is oneof the rst essentials of a good fastener. The shank is engaged bycooperating wood bers in a maximum holding relation, and, due to thecombination with the ilexible head, this holding Arelation ismaintained, even when subjected vto strains incident to expansion andcontraction of the rooting material under extreme weather conditions.

It is well known that freezing of moisture under a rigid nail head willpull the nail. The present invention provides the novel combinationof ai -peculiarly emcient shank which prevents the nail being eased out, anda peculiar type of head having the required flexibility and resilienceto maintain a perfect seal.

It is important that the helical'groove 4 should be of suiiciently lowpitch so that there will be no tendency for the nail to turn during theprocess 4of driving through the roofing and into the wooden sheathing. Astill more important characteristic of the low pitch is that the nailhas no tendency toV ease out as itfcan not be moved until the maximumpulling power is applied. Furthermore, although it has been found thatannular non-helical grooves of a contour similar to the helical grooveillustrated will provide increased holding power, such grooves presentdimculties in the process of lgalvanizing the nails, as the suraisaavoplus coating does not drain freely. The single continuous elongatedgroove overcomes these difculties by providing a continuous path for theflow or drainage of the galvanizing material G and causes the materialto form a thin, smooth, and substantially uniform coating over theentire 4,surface of-the groove, as shown in Fig. 5. at, the

same time this type of groove does not present any increased resistanceto the driving of the nail and materially increases the holding powerafter it is in place.

Careful tests have shown that nails made in accordance with the presentinvention have more than three times the holding power oi ordinary highpitch threaded nails and that the thin heads cooperate therewith toprovide an em'cient seal. The nails do not ease out but become loosenedonly when maximum pulling power is applied whereby they break looseentirely from the wood fibers. The'factor of safety is so great,however, that they do not become loosened under ordinary `onditions ofuse. In comparative tests, nails with high pitch threads, which causethe nails to rotate, ease out under a continuous two hundred and ftypound pull, while the same size nails made in accordance with thisinvention resist up to ve hundred pounds pull without movement and thensuddenly pop completely out.

The helical groove is preferably comparatively shallow and the crosssectional strength of thel nail is not materially weakened, as thematerial from the groove is merely pressed outwardly to form theshoulder, and the nail retains substanltially the same cross sectionalarea at all points.

The nails 'are preferably formed by irst 11p-5 f setting thereon a verythin head to the required dimensionskand then rollingthe shank to formthe helical high pitch groove. 'I'he shank of the nail is very small incross section, and this method all@ of forming the groove and shoulderleaves the process of upsetting the head.

Figs. 3 and 4 illustrate the use'oi' the nails in connection with verythin veneered material for which they are particularly adapted, as thelong helical shoulder hooks under a maximum number of bers over itsentire length. The flbeware not materially injured by the'entering nail,but are merely pressed outwardly by the' inclined surface of the grooveand theirl resilience causes them to engage snugly in the groove andover the top of the shoulder. Fig. 3 is an enlarged view drawn to scaleof five ply veneer five-eighths of an inch thick, While Fig. 4 is anenlarged scale drawing of three-eighths of an inch threeply veneer:

The nails are preferably completely covered with a galvanized metalcoating G (Fig. 5) which also assists in providing asurface suitable foremcient engagement of the wood fibres therewith and prevents oxidationof the entire nail under all weather conditions. When the nail is drivenvertically into the sheathing the extreme thinness of the head, which ispreferably malleable will cause it to adjust itself to slight variationsin the thickness of the roll roong or to irregularities in the surfaceof the sheathing.

These nails are usually driven very rapidly by f7! the roofer and arevery often somewhat angularly disposed relative to the sheathing. Anyangular displacement of a rigid-head nail while being driven causes thehead to cut or distort the roll roofing and also to exert its greatestclamping pressure upon the lowest portion leaving the opposite sidetilted upwardly whereby moisture enters under the head of the nail andmay even enter the sheathing around the shank. This destroys theeiliciency of the nail in a short time and is particularly undesirablein cold weather as the moisture freezes under the head of the nail andcauses the nail to raise or pop and ultimately become entirely removed.

In applicants device, as mentioned previously, the head isrelativelylarge in diameter and very thin, and as it is made of malleable materialit is easily bent or deformed to fit the irregularities in the roofingor sheathing and will assume an angular position relative to the shankand parallel with the surface of the roofing even when the nail isdriven into the sheathing at a considerable angle thereto. 'I'he head,however, while malleable and capable of conforming to the irregularitiesis suiliciently rigid and resilient to maintain the roll roofingsecurely clamped against the sheathing and overthe entire lower area ofthe head. The material of the nail, the

lfinish, and the dimensions of its component parts are so correlated' asto cooperatively function in a manner to maintain the nail snugly inposition and to prevent the access of moisture thereto for aconsiderably longer period than heretofore possible.

Satisfactory nails may be made in which the ratio of the diameter of theshank to the head may be on the order of 1 to 5 and the head may be ofuniform thickness and substantially twentyfive thousandths inch thick.The ratio of the thickness of the head to the diameter thereof ispreferably substantially 1 to 30.

Modifications will be apparent to those skilled in the art, and it isdesired, therefore, that the invention be limited only by the prior artand the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In a non-rotating nail for securing roll roofing to thin sheathing,the combination with a short shank having a thread extending oversubstantially the entire sheathing engaging portion thereof, said threadbeing of sufliciently low pitch to prevent rotation during driving orpulling, of a relatively large integral thin flexible head on saidshank, said head being suiliciently thin to permit it to flex understrains materially less than the holding power ofy said thread instandard thin sheathing.

2. A nail for securing roll roofing to thin sheathing comprising a shortshank having a thin large diameter flexible head of malleable materialconstructed and arranged to seal the opening around the nail shank whenthe nail is driven snugly in place, said shank being provided/ oversubstantially all of that portion engaged by standard thin sheathingwith a continuous helical shoulder of a diameter not less than theoriginal diameter of said shank and arranged to be engaged by woodfibers when driven therein to materiallyresist pulling of the nailbeyond the ilexing resistance of the head, the surface of said nailbelow and adjacent said shoulder being inwardly tapered to enable easydriving of the nail, said helical shoulder being constructed andarranged to enable driving or pulling without rotation, and terminatingshort of the point of said shank to provide a cylindrical pilot portion.

3. In a non-rotating nail for securing roll roofing to thin sheathing,the combination with a short pointed shank having an anfractuousshoulder thereon extending over substantially the entire sheathingengaging portion of said shank and terminating short of said head, theupper surface of said -shoulder being substantially perpendicular to theaxis of said shank, of an integral malleable head on said shank, saidhead being suiliciently thin over its entirearea to conform to thesurface of a substantially flat roof when the nail is driven angularlytherein by the normal blow of a hammer and to permit flexible adjustmentin accordance with irregularities of said roofing, said shank betweensaid head and said shoulder being tapered toward said shoulder andhaving an external dimension adjacent said head substantially equal tothe maximum external dimension of said shoulder.

4 4. A non-rotating nail for securing roll rooflng to thin sheathing,comprising a short pointed shank having a relatively large flat headintegral therewith, said head being suiiiciently thin and flexible toconform to the surface of a substantially flat roof when the nail isdriven therein by the normal blows of a hammer, and to permit exibleadjustment in accordance with irregularities of said roofing, sand shankhaving a thread extending over substantially the entire sheathingengaging portion of its length and terminating short of said head, saidthread being of sumciently low pitch to prevent rotation during drivingor pulling, said shank between said head and said thread being taperedtoward said thread and hav- .ing an external dimension closely adjacentsaid head substantially the same as the outside diameter of said thread.

5. In a fastener for securing roll roofing to thin sheathing thecombination with a short small diameter pointed shank, of a relativelyvery large diameter flexible head integral therewith, said shank havinga helical V-shaped groove in said shank and covering substantially theentire sheathing engaging portion thereof adjacent the point of saidnail, the convolutions of said groove being closely adjacent and of suchpitch that the nail will not rotate when driven, and a relativelyuniform coating of .galvanizing material covering said nail, saidconvolutions terminating short ofl the point of said shank to provide acylindrical pilot therebetween. l

6. A non-rotating nail for securing roll roofing to thin sheathingcomprising a short pointed shank having a relatively very large flathead integral therewith, said head being sufficiently thin and flexibleto conform to the surface of a substantialy flat roof when the nail isdriven therein by the normal blows of a hammer, and to permit flexibleadjustment in accordance with irregularities of said roofing, said shankhaving a thread extending over the major portion of its length andterminating short of said head and said point, said thread being ofsuiliciently low pitch to prevent rotation during driving or pulling ofsaid nail, said shank between said head and said thread being taperedtoward said thread and having a transverse thickness closely adjacentsaid head at least equal to the outside diameter of said thread, and acylindrical pilot portion between said vthread and the point ofy saidshank.

y HAMILTON M. MAZE.

